Wash the mushrooms and dry them. Cut them in half (if mushrooms are large cut them into larger pieces). Place in a suitable container the butter and the oil to heat and add the mushrooms. Fry the mushrooms until they brown - about 10 minutes, stir occasionally. Cut bacon and chopped parsley, crushed garlic, add them breadcrumbs, salt and pepper and sprinkle the mushrooms with this mixture, stir and reduce the heat to fry the mushrooms for 10 minutes on low flame as though stirring occasionally. Finally, add the lemon juice, stir and remove from fire. Serve while hot as a side dish, appetizer or main dish.